Shape memory polymers (SMPs) are polymers whose qualities have been altered to give them dynamic shape "memory" properties. Using thermal or other stimuli, SMP can exhibit a radical change from a rigid polymer to a very elastic state, then back to a rigid state again. In its elastic state, it will recover its "memory" shape if left unrestrained. However, while pliable it can be stretched, folded, or otherwise conformed to other shapes, tolerating up to 200% elongation without degradation of the material. The "memory," or recovery, quality comes from the stored mechanical energy attained during the reconfiguration and cooling of the material.
SMP can be cast and cured into any "memorized" shape, from a thick sheet, to a concave dish, to a complicated open honeycomb network. SMP can also be used as a coating on another material. This versatility makes SMP ideal for applications such as dynamic configurable parts, deployable components, and inexpensive, reusable custom molds. Shape memory characteristics can be engineered into most polymers. Some of CRG's SMP formulations were based on styrene acrylate, cyanate ester, and epoxy polymer systems.
CRG has commercialized SMP through the creation of spin-off subsidiaries that focus on incorporating SMP-based technologies into products and manufacturing processes. Commercialization can also take the form of licensing agreements or the formation of joint ventures. CRG’s business model does not include the sale of SMP material outside of a license agreement. See our Commercialization Center to learn how CRG markets and commercializes research results.
Some other applications of SMP may include reusable molds, deployable mechanisms and structures, adjustable furniture, reformable toys, customized containers, adjustable shipping and packaging, actuators, sensors, space-qualifiable applications, and a variety of automotive components.
CRG has led shape memory polymer research for over 15 years and has developed a large patent portfolio based on this technology:
- Shape Memory Styrene Copolymers, US Pat. No. 6,759,481
- Structural and Optical Application for SMP, US Pat. No. 6,986,855
- Maleimide-Based High-Temp SMP, US Pat. No. 7,276,195
- Shape Memory Mandrel, US Pat. No. 7,422,714.
See CRG’s subsidiary, Spintech LLC, to learn more about commercialized shape memory technologies, such as mandrels (Smart Tooling) and SMP-based composite repair products and materials.